What is the highest possible bounce for a Superball?

[Oakminster]

Yeah, the shattering thing kinda puts a damper on the cannon theory. Maybe one of those pitching machines like they use in batting cages, dialed up in increments until we reach the shatter-point, would prove useful…

[ivn1188]

@Oakminster

Yeah, the shattering thing kinda puts a damper on the cannon theory. Maybe one of those pitching machines like they use in batting cages, dialed up in increments until we reach the shatter-point, would prove useful…

Well, all you really need to do is put it in a crush tester. Not as sexy, but much more accurate.

[Machine_Elf]

@kunilou

It is entirely possible to shatter a Super Ball by hitting it hard enough with a baseball bat. It’s kinda cool actually, since the individual shards bounce when they hit the ground, but it does pose a limit to the Barry Bonds vs. 100 mph fastball experiment.

Some other folks found the limit for Silly Putty.

[AncientHumanoid]

Whatever you do, DON’T TAUNT IT!

[billfish678]

I found one of those the other day in a campground. Of course I immediatly started throwing it down as hard as I could to get it to bounce as high as possible. Didnt take too long before I managed to shatter it. My estimate was that I was getting somewhere around 25 feet give or take 5 feet.

[WarmNPrickly]

I think you will need to start with a fresh superball each time. Repeated stress could cause it to break prematurely.

[Quercus]

@ivn1188

The terminal velocity would then be about 34 m/s, or 75 mph. That’s about equal to a fall of 250m. (I’m not showing my math on this one, because I used my calculator’s formula.) So the highest bounce from a dropped ball would be about 215m, give or take, depending the assumptions.

How do you get from 34 m/s terminal velocity to a fall of 250m? I believe in a vacuum, a drop from 59m is enough to get 34 m/s. Is the 250m the drop necessary to get within x% of terminal velocity with air resistance?

At any rate, the bounce is going to be a lot less: after the ball bounces and starts heading up, air resistance is going to be pushing the ball down. So it will go up lower than it would in a vacuum. Since a ball would go up 59m in a vacuum, the height in air will be less than that. Without solving the equation, we can say that the maximum air resistance after the bounce is exactly the same magnitude as gravity, so if air resistance never decreased, the ball would bounce half as high as in a vacuum. But air resistance does decrease, so we can say the ball would bounce somewhere between 30m and 60m high.

[Lanzy]

@pkbites

I had one that bounced all the way up to the moon, off it’s surface, and back down to earth where I caught it in my teeth. Had the moon not been there it probably would have gone all the way up to the sun and melted, so I was lucky to get it back. I first told about my experience with the superball to a group of awe struck children on the playground circa 1968 at the age of 8 years old.
That’s my story, and I’m sticking to it!

You should try throwing one into the Grand Canyon, it goes all over the place before finally coming back to you.

[ivn1188]

@Quercus

How do you get from 34 m/s terminal velocity to a fall of 250m? I believe in a vacuum, a drop from 59m is enough to get 34 m/s. Is the 250m the drop necessary to get within x% of terminal velocity with air resistance?

Yes, it takes 250m-ish to hit about 33 m/s which is ~99% of a the terminal velocity of a 3.0cm sphere with the density of water in air.

@Quercus

At any rate, the bounce is going to be a lot less: after the ball bounces and starts heading up, air resistance is going to be pushing the ball down. So it will go up lower than it would in a vacuum. Since a ball would go up 59m in a vacuum, the height in air will be less than that. Without solving the equation, we can say that the maximum air resistance after the bounce is exactly the same magnitude as gravity, so if air resistance never decreased, the ball would bounce half as high as in a vacuum. But air resistance does decrease, so we can say the ball would bounce somewhere between 30m and 60m high.

I think you are correct. I neglected to account for the fact that terminal-velocity-in-air-ball has the same energy as dropped-from-60-m-in-a-vacuum-ball, so they would bounce the same, minus some height lost due to drag for the ball in air.

The best bounce in vacuum at 33m/s would be ~51m, so the best bounce in air is probably a small bit less than that, subject to the constraint of dropping the ball and the ball being strong enough not to shatter.

[Bewildebeest]

Can you restate the question in the form of a myth?

[pancakes3]

it was this very question that experimentally derived to get the coeficcient of restitution.

the coefficient of restitution in all likelihood wasn’t calculated in a vacuum and is calibrated already to a certain atmospheric pressure against a certain “near 1” CoR material. then consider the variable shapes/sizes of the ball, height dropped, etc. befuddles the 0.92 value even further that we’re probably being as precise as possible with “about 90%.”

[Oslo_Ostragoth]

“SUPERBALL
FACTOID
As a promotional item, Wham-O
once built a giant Superball, which
was accidentally dropped out of a 23rd
floor hotel window in Australia. It shot
back up 15 floors, then down again
into a parked convertible car. The
car was totaled, but the ball survived
the “test” in perfect condition”

http://membership.acs.org/c/chicago/statefair/CD-2008/Chemmatters/2005_10_smpissue.pdf

[Oslo_Ostragoth]

@ivn1188

Superballs have a coefficient of restitution of .92.

COR= sqrt(bounce height/drop height) against a perfectly hard surface.

So, it should bounce to about 85% of its drop height. A 1 meter drop, then, would result in a bounce of 85cm.

Of course, we need to account for air.

The terminal velocity of a superball is pretty easy to calculate:

Vt= sqrt(2mass g\DensityOfAirAreaCoefficientOfDrag)

The drag coefficient for a smooth sphere is about .5, the density of air is 1.29kg/m^3. I don’t know the density of a superball, but it’s probably a little more dense than water, so let’s guesstimate a 3.0 cm ball with waterish density.

The terminal velocity would then be about 34 m/s, or 75 mph.

Hold on - isn’t the terminal velocity of a very-non-aerodynamic human about 120 mph?

I suspect that the density of a superball is about twice that of water.

[Oslo_Ostragoth]

@Mangosteen

I’d like to know how far one would go if a pitcher threw a 100 mph fast ball using a Superball and Bonds hit it as hard as he could with the sweet part of his bat.

Hopefully the ball would start rising immediately so it wouldn’t decapitate the pitcher.

A few miles?

The experiment was performed in the late '60’s by elementary school boys. The answer is “really, really far”. We never did find it.

I imagine Bonds could hit it a half mile at least.

p.s. A similar question was posed in the Mythbusters forum, so maybe they will look at it one day

[NDP]

Maybe it’s because my memory is getting foggy in my old age but I vaguely recall David Letterman dropping some superballs from a 5-story tower back in his “Late Night” days on NBC.

[Machine_Elf]

@Oslo_Ostragoth

Hold on - isn’t the terminal velocity of a very-non-aerodynamic human about 120 mph?

Yes, but a human bean is much heavier. True, a superball has much less drag since it’s so tiny, but it also has much less weight pulling it down, since it’s so tiny.

If you took a spherical superball and made it big enough so that it weighed ~150 pounds, its terminal velocity would probably be considerably greater than 120 MPH (see ivn1188’s equation).

[DrDeth]

We dropped a pack of 5 mini-super balls out of a 12 story window into an alley when I was young and foolish.

At least 3 disintegrated upon impact. One bounced up and broke a window on the opposite building, about the 3rd floor.

So, after a certain height, they just disintegrate upon impact.

[chromaticity]

All this talk of balls bouncing and shattering reminds me of a good sci-fi story by Walter Tevis.
The Big Bounce
Somewhat similar premise.

[jjimm]

@Oslo_Ostragoth

As a promotional item, Wham-O
once built a giant Superball, which
was accidentally dropped out of a 23rd
floor hotel window in Australia. ]

How do you “accidentally” drop a giant superball out of a hotel window? (Unless your name’s Keith Moon.)